Belfast City Council has become the first local authority in Ireland to pass a motion in support of gay marriage.

It was passed by 21 Sinn Fein and SDLP votes to zero — unionists walked out before the vote, while all Alliance councillors except one abstained.

Alliance councillor Catherine Curran voted in favour of the motion, but the rest of her party colleagues said they wanted more time for internal consultation on the issue.

The motion proposed by Sinn Fein’s Mary Ellen Campbell stated: “This council supports the same rights and entitlements to civil marriages for all citizens of Belfast regardless of race, religion or sexuality.”

All DUP and Ulster Unionist councillors left the chamber during the debate at City Hall — except for the DUP Lord Mayor Gavin Robinson, who was chairing the meeting.

He told the chamber: “I have remained here, because in sitting in this chair and holding this office I owe a higher duty than the petty politics which have been played here this evening. That is why I have remained.”

Sinn Fein councillor Conor Maskey told the Belfast Telegraph it was important that Belfast City Council sends out the message everyone is equal.

“It is regrettable that people walked away from such a serious issue. However, we are very happy the motion was passed,” he added.

“It sends out a strong message on pure equality for people in same-sex relationships.

“It should be noted, Belfast is the first local government in Ireland to support a motion like that and hopefully it’s a starting point for a more vigorous campaign to embed this in law.”

John O’Neill, director of the Rainbow Project, based in Belfast — which offers support services to lesbian, gay, bisexual and transgender people in Northern Ireland — said the passing of the marriage equality motion is to be welcomed.

“This is an important step towards ensuring marriage equality for everyone across Northern Ireland regardless of their sexual orientation,” he said.

“While this debate was important — and we hope that similar discussions will be held in councils across Northern Ireland — we hope that the issue will also be discussed at the Northern Ireland Assembly who have the power to extend marriage to couples of the same-sex.”

Factfile

Belfast was the first city in the UK to hold a civil partnership for a gay couple in December 2005, when Grainne Close from Ahoghill and Shannon Sickles got hitched at the City Hall.

The Civil Partnership Act provides same-sex couples with similar legal rights to married couples.

But the law does not allow such unions to be referred to as marriages, and since it was passed, campaigners have pushed for full equality with heterosexual marriage.